Devices of this type, in particular for measuring milk, are known which enable a sample to be taken, the volume of which is substantially proportional to the flow rate. This sample is then analyzed so as to pay the farmer according to the quantity and quality of the milk.
A device of this type is described, for example, in French Pat. No. 1,424,746, but this device suffers two sorts of defect. Firstly, it has to be operated in a perfectly level position so that the factor of proportionality between the flow rate and the volume of the sample taken is constant. It is widely acknowledged that this is a condition which is difficult to meet in a cow shed.
Moreover, as the volume of the sample is determined by reading the depth, it will be understood that this reading cannot be made accurately. In fact, freshly milked milk is a foaming liquid which does not have a clearly defined surface.